1. Field of the Invention
The present invention relates to swimming pool covers, and more particularly to a device for winding up and storing such a cover.
2. Description of the Prior Art
Swimming pool covers are an advantageous accessory for outdoor swimming pools. They are placed on the surface of the water when the swimming pools are not in use for the purpose of insulating the top surface of the water in order to reduce heat loss, particularly at night. A pool cover also reduces the amount of evaporation of the water in the pool and the chemicals in solution therewith, such as chlorine. Accordingly, such swimming pool covers contribute to lowering the cost of operating a swimming pool.
Such covers are usually made of a laminated flexible plastic sheet material with pockets trapping air therein and are at least 4 meters in diameter or square in order to cover all of the surface of the water on the swimming pools. It is not always practical, particularly with a larger pool, to roll tip the cover by hand and simply place it on the side of the pool. Accordingly, a roll-up device for a swimming pool cover is preferably used.
In many cases, the roll-up device is simply a length of aluminum pipe on which the cover is wrapped at an edge and then two persons, one at each end of the pipe, cause the pipe to be rotated, thus rolling up the cover.
Such roll-up devices may include a rigid shaft supported at each end on a pair of posts or brackets. The rigid shaft is spaced above the water surface at one end of the pool if it is a rectilinear pool or oval, and tangential to an above-ground circular pool. An example of such a wind-up device is shown in U.S. Pat. No. 3,777,319, Myles, Dec. 11, 1973. FIG. 3 in this patent shows a typical installation with the wind-up device located at one end of an inground pool.
Such roll-up devices are relatively unsightly and can be an obstruction since access to the pool is prevented from whichever end the device is installed. On above-ground pools, the latter may be less of a problem. However, given that above-ground pools are generally circular, it is almost a necessity that the roll-up device extend diametrically of the pool that is directly over the center. The alternative is to handle the cover manually and remove it on or off the water surface as best one can. Such a solution becomes impractical on larger pool sizes.